Botulism

Overview

• Organism• History• Epidemiology• Transmission• Disease in Humans• Disease in Animals• Prevention and Control

Organism

• Clostridium botulinum– Gram positive– Obligate anaerobic bacillus– Spores• Ubiquitous• Resistant to heat, light, drying and radiation• Specific conditions for germination

– Anaerobic conditions– Warmth (10-50oC)– Mild alkalinity

Neurotoxins

• Seven different types: A through G– Different types affect different species– All cause flaccid paralysis – Only a few nanograms can cause illness– Binds neuromuscular junctions

• Toxin: Destroyed by boiling• Spores: Higher temperatures to be inactivated

NeurotoxinsNeurotoxinNeurotoxin AA BB CC DD EE FF GG

HumanHuman XX XX XX XX

HorsesHorses XX XX

CattleCattle XX XX XX

SheepSheep XX

DogsDogs XX XX

AvianAvian XX XX

Mink & FerretMink & Ferret XX XX XX

History

History

• 1793, Justinius Kerner– “Wurstgift”

• “Botulus” = Latin for sausage• 1895, Emile von Ermengem– Isolated organism during Belgium outbreak

• U.S. outbreaks led to improved industry processing

Transmission

Transmission

• Ingestion– Organism– Spores– Neurotoxin

• Wound contamination• Inhalation• Person-to-person not documented

Epidemiology

Epidemiology

• In U.S., average 110 cases each year– Approximately 25% food-borne– Approximately 72% infant form– Remainder wound form

• Case-fatality rate– 5-10%

• Infective dose- few nanograms

Epidemiology

• 1977, Largest botulism outbreak– Michigan - 59 people– Poorly preserved jalapeno peppers

• Alaska– 27% of U.S. foodborne botulism cases– 1950-2000• 226 cases from 114 outbreaks

Disease in Humans

Human Disease

• Three forms– Foodborne– Wound– Infant

• All forms fatal and a medical emergency• Incubation period: 12-36 hours

Foodborne Botulism

• Preformed toxin ingested from contaminated food

• Most common from home-canned foods – Asparagus, green beans, beets, corn, baked

potatoes, garlic, chile peppers, tomatoes; type A– Improperly fermented fish (Alaska); type E

Year

1982 1987 1992 1997 2002

Report

ed C

ase

s

110

100

90

80

70

60

50

40

30

20

10

0

MMWR

Infant Botulism

• Most common form in U.S.• Spore ingestion– Germinate then toxin released and

colonize large intestine

• Infants < 1 year old– 94% < 6 months old

• Spores from varied sources– Honey, food, dust, corn syrup

1982 1987 1992 1997 2002

Year

110

100

90

80

70

60

50

40

30

20

10

0

Report

ed C

ase

s

MMWR

Wound Botulism

• Organism enters wound– Develops under anaerobic conditions– From ground-in dirt or gravel– It does not penetrate intact skin– Associated with addicts of black-tar heroin

Adult Clinical Signs

• Nausea, vomiting, diarrhea• Double vision• Difficulty speaking or swallowing• Descending weakness or paralysis– Shoulders to arms to thighs to calves

• Symmetrical flaccid paralysis• Respiratory muscle paralysis

Infant Clinical Signs

• Constipation• Lethargy• Poor feeding• Weak cry• Bulbar palsies• Failure to thrive

Diagnosis

• Clinical signs• Toxin in serum, stool, gastric aspirate,

suspected food• Culture of stool or gastric aspirate– Takes 5-7 days

• Electromyography also diagnostic• Mouse neutralization test– Results in 48 hours

Treatment

• Intensive care immediately– Ventilator for respiratory failure

• Botulinum antitoxin– Derived from equine source– CDC distributes– Used on a case-by-case basis

• Botulism immune globulin– Infant cases of types A and G

Animals andBotulism

Animals

• Cattle and sheep• Horses• Birds and poultry• Mink and ferrets• Uncommon in dogs and pigs– Fairly resistant

• No natural cases documented in cats

Cattle and Sheep

• Ingestion of toxin• Incubation– 24 hours to 7 days

• Sources– Spoiled stored silage or grain– Silage using poultry litter or products– Phosphorus deficiency in cattle– Carcasses: Baled or chopped into hay

Ruminants: Clinical Signs• Progressive ascending ataxia• Recumbent• Head turned into flanks • Cranial nerve dysfunction• Rumen stasis; bloat• Atonic bladder - loss of urination

Cattle and Sheep: Diagnosis

• History• Bloodwork and CSF tap: Normal• ELISA test available for type C & D• Definitive diagnosis– Demonstration of toxin in serum, gut contents or

organs

• Electromyography (EMG)

Cattle and Sheep: Treatment

• Symptomatic and supportive• Nutritional• Ventilatory support, if needed• Metronidazole• Antitoxin, in early stages– Ineffective by the time clinical signs are present– Can block further uptake of toxin

Horses

• Horses, especially foals, are highly sensitive to botulism toxin

• Type B & C toxins• Incubation period– 24 hours to 7 days

• Sources– Contaminated feed– Wound infections

Adult Horses

• “Forage poisoning”– Ingest preformed toxin

• Clinical Signs– Dyspnea– Flaccid tail– Muscle tremors– Severe paresis to rapid recumbency– Unable to retract tongue, drooling

Foals

• “Shaker Foal” syndrome– Most 2 weeks to 8 months old– On a high nutrition plane

• Spores in contaminated feed• Usually type B– Most common in KY and eastern seaboard

Foals: Clinical Signs

• Clinical signs– Paresis, recumbent– Muscle tremors– Dysphagia– Ptosis, mydriasis, decreased PLR– Ileus, constipation, urine retention– Death due to respiratory paralysis

• Mortality greater than 90%

Birds and Poultry

• “Limber neck”• Types C and E• Good sentinel species• Sources:– Decomposed vegetation or invertebrates– Ingest toxin or invertebrates with toxin– Contaminated feed or water of chickens

Birds and Poultry:Clinical Signs

• Occurs 12-48 hours after ingestion• Droopy head• Drowsy• Wing and leg paralysis– Unable to hold their head up– Unable to use their wings or legs

• Eyelid paralysis

Mink and Ferrets

• Type C– Occasionally A and E

• Sources– Chopped raw meat or fish– Improper storage of meat by-products

• Vaccine available for type C

Dogs

• Rare• Type C; few cases type D• Source– Ingestion of carrion– Wetland areas with avian botulism epizootics

• Incubation period– Few hours to 6 days

Dogs

• Progressive symmetric ascending weakness– Rear limbs to forelimbs

• Cranial nerve deficits• Respiratory paralysis• Lose ability to urinate and defecate

Dogs

• Diagnosis– Bloodwork and CSF: Normal– Electromyography (EMG)– Toxin in serum, vomitus, feces, or suspect

food/carrion – Mouse neutralization test preferred

• Treatment– Supportive– Antitoxin

Prevention and Control

Human: Prevention

• Do not feed honey to children <1 yr of age• Proper food preservation methods

• Proper time, temperature and pressure– 80oC for 30 min or 100oC for 10 min

• Prompt refrigeration of foods• Boil foods for > 10 minutes• Decontamination– Boil suspected food before discarding– Boil or chlorine disinfect utensils used

Ruminants: Prevention

• Good husbandry practices• Rodent and vermin control• Prompt disposal of carcasses• Avoid spoiled feedstuff or poor quality silage• Vaccination in endemic areas

Equine: Prevention

• Good husbandry• Rodent and vermin control• Avoid spoiled feed • Prophylactic vaccine for pregnant mares– Currently only type B botulinum toxoid available

for horses

Potential Bioterrorism Threat

• Aum Shinriky cult• Extremely potent and lethal• Easily produced and transported• Signs of deliberate aerosol or foodborne

release of toxin– No common source – Large number of acute cases clustered– Uncommon toxin type (C, D, F, G)

Potential Bioterrorism Threat

• Point source aerosol release– Incapacitate or kill 10% of persons within 0.5 km

downwind

• CDC surveillance system– Prompt detection of botulism related events